Hydrogenation of benzene polycarboxylic acids or derivatives thereof

ABSTRACT

A process for hydrogenating benzenepolycarboxylic acids or derivatives thereof, such as esters and/or anhydrides, by bringing one or more benzenepolycarboxylic acids or one or more derivatives thereof into contact with a hydrogen-containing gas in the presence of one or more catalytically active metal, such as platinum, palladium ruthenium or mixtures thereof, deposited on a catalyst support comprising one or more ordered mesoporous materials.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. Ser. No. 10/535,531, filedJun. 2, 2006, now U.S. Pat. No. 7,595,420, which claims priority fromInternational Application No. PCT/EP2003/012881, filed Nov. 18, 2003,which claims benefit of Great Britain Application No. 0227087.4, filedNov. 20, 2002. These applications are incorporated by reference herein.

FIELD OF INVENTION

The present invention relates to a process for the hydrogenation ofbenzenepolycarboxylic acids or derivatives thereof, such as estersand/or anhydrides, and in particular to a hydrogenation process, whichutilizes a catalyst based on the combination of one or morecatalytically active metals with one or more ordered mesoporousmaterials as support.

BACKGROUND OF THE INVENTION

Hydrogenation is an established process both in the chemical andpetroleum refining industries. Hydrogenation is conventionally carriedout in the presence of a catalyst, which usually comprises a metalhydrogenation component deposited on a porous support material. Themetal hydrogenation component is often nickel or one or more metals suchas platinum, palladium, rhodium or ruthenium.

Hydrogenated derivatives of benzenepolycarboxylic acids or derivativesthereof, such as esters and/or anhydrides, have many uses. Of particularinterest is their use as plasticisers for polymeric materials. In thiscontext the dialkylhexahydrophthalates are an example of one class ofthese compounds that are of particular interest. These materials may beproduced by hydrogenation of the corresponding phthalic acid ester inthe presence of hydrogen and an active metal hydrogenation catalystdeposited on a support.

In U.S. Pat. No. 5,286,898 and U.S. Pat. No. 5,319,129,dimethylterephthalate is hydrogenated at ≧140° C. and a pressure of from50 to 170 bar over supported Pd catalysts, which are treated with Ni, Ptand/or Ru to give the corresponding dimethylhexahydroterephthalate. Thesupports used are alumina of crystalline phase alpha or theta or deltaor gamma or beta or mixtures thereof.

In EP-A-0 005 737, aromatic carboxylic esters are hydrogenated at from70 to 250° C. and from 30 to 200 bar over supported Ni, Ru, Rh and/or Pdcatalysts to give the corresponding cycloaliphatic carboxylic esters.The support used is an aluminium oxide of which at least 20% has beenconverted into lithium-aluminium spinel.

U.S. Pat. No. 3,027,398 describes the hydrogenation ofdimethylterephthalate over supported Ru catalysts at from 110 to 140° C.and from 35 to 105 bar. The Ru is deposited on charcoal or kieselguhr.

EP-A 0 603 825 relates to a process for the preparation of1,4-cycylohexanedicarboxylic acid by hydrogenating terephthalic acid byusing a supported palladium catalyst, wherein as support alumina, silicaor active charcoal is used.

U.S. Pat. No. 3,334,149 describes a multistage process for thehydrogenation of dialkylterephthalate using a Pd catalyst followed byuse of a copper chromite catalyst.

U.S. Pat. No. 5,936,126 describes a process for the hydrogenation of anaromatic compound. The catalyst used contains ruthenium as active metalalone or optionally with one or more other Group IB, VIIB or VIIIBmetals on a macroporous support. The macroporous support exhibits anaverage pore diameter of at least 50 nm and a BET surface area of notmore than about 30 m²/g.

U.S. Pat. No. 6,248,924 describes a process for reacting organiccompounds. The catalyst used contains ruthenium as active metal alone oroptionally with one or more other Group IB, VIIB or VIIIB metals on asupport. The support may be a material having macropores (50 to 10000 nmpore diameter) and mesopores (2 to 50 nm pore diameter). In the support10-50% of the pores are macropores and 50 to 90% of the pores aremesopores. Alumina of surface area (BET) 238 m²/g is specificallyexemplified.

Published International Application No. PCT/EP98/08346 (WO 99/32427)describes a process for the hydrogenation of benzene polycarboxylicacids or derivatives thereof. The catalyst used comprises ruthenium asan active metal which is deposited alone or together with at least oneother metal of subgroups I, VII or VIII of the periodic table on asupport. One of three separate types of support may be used. The firstsupport is macroporous having a mean pore diameter of at least about 50nm and a BET surface area of at most 30 m²/g. The second support is amaterial, which has both macropores and mesopores (2 to 50 nm porediameter), and in which 5-50% of the pores are macropores, 50 to 95% ofthe pores are mesopores and the surface area of the support ispreferably from 50 to about 500 m²/g. The third type of support is amaterial, which is macroporous and has a mean pore diameter of at least0.1 lm and a surface area of at most 15 m²/g.

Of particular importance in the hydrogenation of benzenepolycarboxylicacids or derivatives thereof is the degree of conversion of the startingmaterials and the selectivity of conversion into the desiredhydrogenated cyclohexyl derivatives. The degree of conversion should beas high as possible and typically conversion levels of greater than 95%are sought and achieved for these types of hydrogenation. However, inthese types of hydrogenation whilst high conversions may be obtained itis difficult to simultaneously achieve the required high degree ofselectivity to the desired product. In this regard there is a problemwith the generation of low molecular weight and/or boiling pointby-products during the hydrogenation reaction. These by-products areoften referred to as “lights” and they must be removed from thehydrogenation product before it is used for example as a plasticiser.

There is a need therefore for new hydrogenation processes for theconversion of benzenepolycarboxylic acids or derivatives to thecorresponding ring-hydrogenated derivatives, which produce lower levelsof “lights” by-products and thus result in improved selectivity for thedesired products. It is therefore, an object of the present invention toprovide a process for hydrogenating benzenedicarboxylic esters oranhydrides, using specific catalysts, by means of which thecorresponding, hydrogenation products may be obtained with high levelsof conversion and selectivity.

SUMMARY OF THE INVENTION

The present invention accordingly provides a process for hydrogenatingone or more benzenepolycarboxylic acids or one or more derivativesthereof, or a mixture of one or more benzenepolycarboxylic acids or oneor more derivatives thereof by bringing the benzenepolycarboxylic acidor the derivative thereof or the mixture into contact with ahydrogen-containing gas in the presence of a catalyst, the catalystcomprising one or more catalytically active metals applied to a catalystsupport comprising one or more ordered mesoporous materials.

In a further aspect the catalyst support comprises one or moremacroporous materials combined in admixture with the one or more orderedmesoporous materials.

In a further aspect the catalyst support comprises one or more mixedporosity materials combined in admixture with the one or more orderedmesoporous materials.

In a further aspect the catalyst comprises as active metal at least onemetal of transition group VIII of the Periodic Table either alone ortogether with at least one metal of transition group I or VII of thePeriodic Table.

DETAILED DESCRIPTION OF THE INVENTION

In the process of the present invention benzenepolycarboxylic acids orderivatives thereof are hydrogenated to the corresponding cyclohexylderivative in the presence of hydrogen and a catalyst comprising anactive hydrogenation metal component deposited on one or more orderedmesoporous materials. We have found that a certain class of supportmaterials, namely ordered mesoporous materials, which have high porevolume, high surface area and controlled pore openings of at least 2 nm,are particularly suitable for the hydrogenation of benzenepolycarboxylicacids or derivatives thereof.

The term “benzenepolycarboxylic acid or a derivative thereof” used forthe purposes of the present invention encompasses allbenzenepolycarboxylic acids as such, e.g. phthalic acid, isophthalicacid, terephthalic acid, trimellitic acid, trimesic acid, hemimelliticacid and pyromellitic acid, and derivatives thereof, particularlymonoesters, diesters and possibly triesters and tetraesters, inparticular alkyl esters, and anhydrides such as phthalic anhydride ortrimellitic anhydride or their esters. The esters used are alkyl,cycloalkyl and alkoxyalkyl esters, where the alkyl, cycloalkyl andalkoxyalkyl groups generally have from 1 to 30, preferably from 2 to 20and particularly preferably from 3 to 18, carbon atoms and can bebranched or linear.

One class of suitable benzenepolycarboxylic acids or a derivativesthereof are the alkyl terephthalates such as monomethyl terephthalate,dimethyl terephthalate, diethyl terephthalate, di-n-propylterephthalate, di-n-butyl terephthalate, di-tert-butyl terephthalate,diisobutyl terephthalate, monoglycol esters of terephthalic acid,diglycol esters of terephthalic acid, di-n-octyl terephthalate,diisooctyl terephthalate, mono-2-ethylhexyl terephthalate,di-2-ethylhexyl terephthalate, di-n-nonyl terephthalate, diisononylterephthalate, di-n-decyl terephthalate, di-n-undecyl terephthalate,diisodecyl terephthalate, diisoundecyl terephthalate, diisododecylterephthalate, di-n-octadecyl terephthalate, diisooctadecylterephthalate, di-n-eicosyl terephthalate, ditridecyl terephthalate,diisotridecyl terephthalate, monocyclohexyl terephthalate and ordicyclohexyl terephthalate. Also suitable are derivates in which thealkyl groups of the ester groups are different alkyl groups. Mixtures ofone or more alkyl terephthalates may be used.

Another suitable class are the alkyl phthalates such as monomethylphthalate, dimethyl phthalate, diethyl phthalate, di-n-propyl phthalate,di-n-butyl phthalate, di-tert-butyl phthalate, diisobutyl phthalate,monoglycol esters of phthalic acid, diglycol esters of phthalic acid,di-n-octyl phthalate, diisooctyl phthalate, di-2-ethylhexyl phthalate,di-n-nonyl phthalate, diisononyl phthalate, di-n-decyl phthalate,diisodecyl phthalate, di-n-undecyl phthalate, di-isoundecyl phthalate,diisododecyl phthalate, di-n-octadecyl phthalate, diisooctadecylphthalate, di-n-eicosyl phthalate, monocyclohexyl phthalate,dicyclohexyl phthalate; alkyl isophthalates such as monomethylisophthalate, dimethyl isophthalate, diethyl isophthalate, di-n-propylisophthalate, di-n-butyl isophthalate, di-tert-butyl isophthalate,diisobutyl isophthalate, monoglycol esters of isophthalic acid, diglycolesters of isophthalic acid, di-n-octyl isophthalate, diisooctylisophthalate, di-2-ethylhexyl isophthalate, di-n-nonyl isophthalate,diisononyl isophthalate, di-n-decyl isophthalate, diisodecylisophthalate, di-n-undecyl isophthalate, di-isoundecyl isophthalate,diisododecyl isophthalate, di-n-octadecyl isophthalate, diisooctadecylisophthalate, di-n-eicosyl isophthalate, monocyclohexyl isophthalate andor dicyclohexyl isophthalate. Also suitable are derivates in which thealkyl groups of the ester groups are different alkyl groups. Mixtures ofone or more alkyl phthalates or isophthalates may be used.

A further suitable class are the alkyl trimellitates such as monomethyltrimellitate, dimethyl trimellitate, diethyl trimellitate, di-n-propyltrimellitate, di-n-butyl trimellitate, di-tert-butyl trimellitate,diisobutyl trimellitate, the monoglycol ester of trimellitic acid,diglycol esters of trimellitic acid, di-n-octyl trimellitate, diisooctyltrimellitate, di-2-ethylhexyl trimellitate, di-n-nonyl trimellitate,diisononyl trimellitate, di-n-decyl trimellitate, diisodecyltrimellitate, di-n-undecyl trimellitate, di-isoundecyl trimellitate,diisododecyl trimellitate, di-n-octadecyl trimellitate, diisooctadecyltrimellitate, di-n-eicosyl trimellitate, monocyclohexyl trimellitate,dicyclohexyl trimellitate and trimethyl trimellitate, triethyltrimellitate, tri-n-propyl trimellitate, tri-n-butyl trimellitate,tri-tert-butyl trimellitate, triisobutyl trimellitate, triglycol estersof trimellitic acid, tri-n-octyl trimellitate, triisooctyl trimellitate,tri-2-ethylhexyl trimellitate, tri-n-nonyl trimellitate, tri-isononyltrimellitate, tri-n-decyl trimellitate, triisododecyl trimellitate,tri-n-undecyl trimellitate, tri-isoundecyl trimellitate, triisododecyltrimellitate, tri-n-octadecyl trimellitate, triisooctadecyltrimellitate, tri-n-eicosyl trimellitate and tricyclohexyl trimellitate.Also suitable are derivates in which the alkyl groups of the estergroups are different alkyl groups. Mixtures of one or more alkyltrimellitates may be used.

Also suitable are the alkyl trimesates such as monomethyl trimesate,dimethyl trimesate, diethyl trimesate, di-n-propyl trimesate, di-n-butyltrimesate, di-tert-butyl trimesate, diisobutyl trimesate, monoglycolesters of trimesic acid, diglycol esters of trimesic acid, di-n-octyltrimesate, diisooctyl trimesate, di-2-ethylhexyl trimesate, di-n-nonyltrimesate, diisononyl trimesate, di-n-decyl trimesate, diisodecyltrimesate, di-n-undecyl trimesate, di-isoundecyl trimesate, diisododecyltrimesate, di-n-octadecyl trimesate, diisooctadecyl trimesate,di-n-eicosyl trimesate, monocyclohexyl trimesate, dicyclohexyltrimesate, and also trimethyl trimesate, triethyl trimesate,tri-n-propyl trimesate, tri-n-butyl trimesate, tri-tert-butyl trimesate,triisobutyl trimesate, triglycol esters of trimesic acid, tri-n-octyltrimesate, triisooctyl trimesate, tri-2-ethyl-hexyl trimesate,tri-n-nonyl trimesate, tri-isononyl trimesate, tri-n-decyl trimesate,triisododecyl trimesate, tri-n-undecyl trimesate, tri-isoundecyltrimesate, triisododecyl trimesate, tri-n-octadecyl trimesate,triisooctadecyl trimesate, tri-n-eicosyl trimesate and tricyclohexyltrimesate. Also suitable are derivates in which the alkyl groups of theester groups are different alkyl groups. Mixtures of one or more alkyltrimesates may be used

A further suitable class are the alkyl hemimellitates such as monomethylhemimellitate, dimethyl hemimellitate, diethyl hemimellitate,di-n-propyl hemimellitate, di-n-butyl hemimellitate, di-tert-butylhemimellitate, diisobutyl hemimellitate, monoglycol esters ofhemimellitic acid, diglycol esters of hemimellitic acid, di-n-octylhemimellitate, diisooctyl hemimellitate, di-2-ethylhexyl hemimellitate,di-n-nonyl hemimellitate, diisononyl hemimellitate, di-n-decylhemimellitate, diisodecyl hemimellitate, di-n-undecyl hemimellitate,di-isoundecyl hemimellitate, diisododecyl hemimellitate, di-n-octadecylhemimellitate, diisooctadecyl hemimellitate, di-n-eicosyl hemimellitate,monocyclohexyl hemimellitate, dicyclohexyl hemimellitate, and alsotrimethyl hemimellitate, triethyl hemimellitate, tri-n-propylhemimellitate, tri-n-butyl hemimellitate, tri-tert-butyl hemimellitate,triisobutyl hemimellitate, triglycol esters of hemimellitic acid,tri-n-octyl hemimellitate, triisooctyl hemimellitate, tri-2-ethylhexylhemimellitate, tri-n-nonyl hemimellitate, tri-isononyl hemimellitate,tri-n-decyl hemimellitate, triisodecyl hemimellitate, tri-n-undecylhemimellitate, tri-isoundecyl hemimellitate, triisododecylhemimellitate, tri-n-octadecyl hemimellitate, triisooctadecylhemimellitate, tri-n-eicosyl hemimellitate and tricyclohexylhemimellitate. Also suitable are derivates in which the alkyl groups ofthe ester groups are different alkyl groups. Mixtures of one or morealkyl hemimellitates may be used

Another suitable class are the alkyl pyromellitates such as monomethylpyromellitate, dimethyl pyromellitate, diethyl pyromellitate,di-n-propyl pyromellitate, di-n-butyl pyromellitate, di-tert-butylpyromellitate, diisobutyl pyromellitate, monoglycol esters ofpyromellitic acid, diglycol esters of pyromellitic acid, di-n-octylpyromellitate, diisooctyl pyromellitate, di-2-ethylhexyl pyromellitate,di-n-nonyl pyromellitate, diisononyl pyromellitate, di-n-decylpyromellitate, diisodecyl pyromellitate, di-n-undecyl pyromellitate,di-isoundecyl pyromellitate, diisododecyl pyromellitate, di-n-octadecylpyromellitate, diisooctadecyl pyromellitate, di-n-eicosyl pyromellitate,monocyclohexyl pyromellitate, trimethyl pyromellitate, triethylpyromellitate, tri-n-propyl pyromellitate, tri-n-butyl pyromellitate,tri-tert-butyl pyromellitate, triisobutyl pyromellitate, triglycolesters of pyromellitic acid, tri-n-octyl pyromellitate, triisooctylpyromellitate, tri-2-ethylhexyl pyromellitate, tri-n-nonylpyromellitate, tri-isononyl pyromellitate, triisodecyl pyromellitate,tri-n-decyl pyromellitate, tri-n-undecyl pyromellitate, tri-isoundecylpyromellitate, triisododecyl pyromellitate, tri-n-octadecylpyromellitate, triisooctadecyl pyromellitate, tri-n-eicosylpyromellitate, tricyclohexyl pyromellitate, and also tetramethylpyromellitate, tetraethyl pyromellitate, tetra-n-propyl pyromellitate,tetra-n-butyl pyromellitate, tetra-tert-butyl pyromellitate,tetraisobutyl pyromellitate, tetraglycol esters of pyromellitic acid,tetra-n-octyl pyromellitate, tetraisooctyl pyromellitate,tetra-2-ethylhexyl pyromellitate, tetra-n-nonyl pyromellitate,tetraisododecyl pyromellitate, tetra-n-undecyl pyromellitate,tetraisododecyl pyromellitate, tetra-n-octadecyl pyromellitate,tetraisooctadecyl pyromellitate, tetra-n-eicosyl pyromellitate,tetracyclohexyl pyromellitate. Also suitable are derivates in which thealkyl groups of the ester groups are different alkyl groups. Mixtures ofone or more alkyl pyromellitates may be used.

Also suitable are anhydrides of phthalic acid, trimellitic acid,hemimellitic acid and pyromellitic acid.

Also suitable are alkyl terephthalates, alkyl phthalates, alkylisophthalates, dialkyl or trialkyl trimellitates, dialkyl or trialkyltrimesates, dialkyl or trialkyl hemimellitates and dialkyl, trialkyl ortetraalkyl pyromellitates in which one or more of the alkyl groupscontain 5, 6 or 7 carbon atoms (e.g. are C₅, C₆ or C₇ alkyl groups) suchalkyl groups include; n-pentyl, 1-methylbutyl terephthalate,2-methylbutyl, 3-methylbutyl, 2,2-dimethylpropyl, 1,1-dimethylpropyl,n-hexyl, 1-methylpentyl, 2-methylpentyl, 3-methylpentyl, 4-methylpentyl,1,1-dimethylbutyl, 2,2-dimethylbutyl, 3,3-dimethylbutyl,1,2-dimethylbutyl, 1,3-dimethylbutyl, 2,3-dimethylbutyl,1-methyl-2-ethylpropyl, 1-ethyl-2-methylpropyl, 1-ethylbutyl,2-ethylbutyl, n-heptyl, 1-methylhexyl, 2-methylhexyl, 3-methylhexyl,4-methylhexyl, 5-methylhexyl, 1,1-dimethylpentyl, 2,2-dimethylpentyl,3,3-dimethylpentyl, 4,4-dimethylpentyl, 1-ethylpentyl, 2-ethylpentyl,3-ethylpentyl, 1,1,2-trimethylbutyl, 1,1,3-trimethylbutyl,1,2,2-trimethylbutyl, 2,2,3-trimethylbutyl, 1,3,3-trimethylbutyl,2,3,3-trimethylbutyl, 1,2,3-trimethylbutyl, 1-ethyl-2-methylbutyl,1-ethyl-3-methylbutyl, 2-ethyl-3-methylbutyl and 1-methyl-2-ethylbutyl.Also envisaged as suitable are compounds in which the alkyl groups arenot identical such as for example in butylpropyl terephthalate or whereone of the alkyl groups is replaced by a benzyl group such as forexample in butylbenzyl terephthalate. Also suitable are mixtures of oneor more alkyl terephthalates, alkyl phthalates, alkyl isophthalates,dialkyl or trialkyl trimellitates, dialkyl or trialkyl trimesates,dialkyl or trialkyl hemimellitates and dialkyl, trialkyl or tetraalkylpyromellitates in which one or more of the alkyl groups contain 5, 6 or7 carbon atoms.

In the process of the present invention it is also possible to usemixtures of one or more of the benzenepolycarboxylic acid or aderivative thereof described herein. When the derivatives are esters themixture may be derived through use of a two or more alcohols inadmixture or in sequence to esterify the same sample of abenzenepolycarboxylic acid derivative or a mixture of two or morebenzenepolycarboxylic acids or a derivatives. Alternatively the alcoholsmay be used to form, in separate syntheses, two different esterifiedderivatives, which may then be mixed together to form a mixture of twoor more esterified derivatives. In either approach the mixture maycomprise a mixture of esters derived from branched or linear alcohols,for example the mixture may comprise ester derivatives prepared from C7,C9, C8, C10 and C11 linear or branched alcohols, preferably linearalcohols, with the alcohols being used in the same synthesis of amixture of derivatives or in separate syntheses of the derivative wherethe resultant derivative products in each synthesis are combined to forma mixed derivative.

In the process of the present invention the preferred products are thosederived from phthalates and in particular the following:cyclohexane-1,2-dicarboxylic acid di(isopentyl)ester, obtainable byhydrogenation of a di(isopentyl)phthalate having the Chemical Abstractsregistry number (in the following: CAS No.) 84777-06-0;cyclohexane-1,2-dicarboxylic acid di(isoheptyl)ester, obtainable byhydrogenating the di(isoheptyl)phthalate having the CAS No. 71888-89-6;cyclohexane-1,2-dicarboxylic acid di(isononyl)ester, obtainable byhydrogenating the di(isononyl)phthalate having the CAS No. 68515-48-0;cyclohexane-1,2-dicarboxylic acid di(isononyl)ester, obtainable byhydrogenating the di(isononyl)phthalate having the CAS No. 28553-12-0,which is based on n-butene; cyclohexane-1,2-dicarboxylic aciddi(isononyl)ester, obtainable by hydrogenating the di(isononyl)phthalatehaving the CAS No. 28553-12-0, which is based on isobutene; a1,2-di-C₉-ester of cyclohexanedicarboxylic acid, obtainable byhydrogenating the di(nonyl)phthalate having the CAS No. 68515-46-8;cyclohexane-1,2-dicarboxylic acid di(isodecyl)ester, obtainable byhydrogenating a di(isodecyl)phthalate having the CAS No. 68515-49-1;1,2-C₇₋₁₁-ester of cyclohexanedicarboxylic acid, obtainable byhydrogenating the corresponding phthalic acid ester having the CAS No.68515-42-4; 1,2-di-C₇₋₁₁-ester of cyclohexanedicarboxylic acid,obtainable by hydrogenating the di-C₇₋₁₁-phthalates having the followingCAS Nos.: 111381-89-6, 111381-90-9, 111381-91-0, 68515-44-6, 68515-45-7and 3648-20-7; a 1,2-di-C₉₋₁₁-ester of cyclohexanedicarboxylic acid,obtainable by hydrogenating a di-C₉₋₁₁-phthalate having the CAS No.98515-43-5; a 1,2-di(isodecyl)cyclohexanedicarboxylic acid ester,obtainable by hydrogenating a di(isodecyl)phthalate, consistingessentially of di-(2-propylheptyl)phthalate;1,2-di-C₇₋₉-cyclohexanedicarboxylic acid ester, obtainable byhydrogenating the corresponding phthalic acid ester, which comprisesbranched and linear C₇₋₉-alkylester groups; respective phthalic acidesters which may be e.g. used as starting materials have the followingCAS Nos.: di-C₇₋₉-alkylphthalate having the CAS No. 111 381-89-6;di-C₇-alkylphthalate having the CAS No. 68515-44-6; anddi-C₉-alkylphthalate having the CAS No. 68515-45-7.

More preferably, the above explicitly mentioned C₅₋₇, C₉, C₁₀, C₇₋₁₁,C₉₋₁₁ and C₇₋₉ esters of 1,2-cyclohexanedicarboxylic acids arepreferably the hydrogenation products of the commercially availablebenzenepolycarboxylic acid esters with the trade names Jayflex® DINP(CAS No. 68515-48-0), Jayflex® DIDP (CAS No. 68515-49-1), Jayflex® DIUP(CAS No. 85507-79-5), Jayflex® DTDP (CAS No. 68515-47-9), Palatinol®911P, Vestinol® 9 (CAS No. 28553-12-0), TOTM-I® (CAS No. 3319-31-1),Linplast® 68-TM and Palatinol® N (CAS No. 28553-12-0) which are used asplasticizers in plastics.

Further examples of commercially available benzenepolycarboxylic acidesters suitable for use in the present invention include phthalates suchas: Palatinol® AH (Di-(2-ethylhexyl)phthalate; Palatinol® AH L(Di-(2-ethylhexyl)phthalate); Palatinol® C (Dibutyl phthalate);Palatinol® IC (Diisobutyl phthalate); Palatinol® N (Diisononylphthalate); Palatinol® Z (Diisodecyl phthalate) Palatinol® 10-P(Di-(2-Propylheptyl)phthalate); Palatinol® 711P (Heptylundecylphthalate); Palatinol® 911 (Nonylundecyl phthalate); Palatinol® 11P-E(Diundecyl phthalate); Palatinol® M (Dimethyl phthalate); Palatinol® A(Diethyl phthalate); Palatinol® A (R) (Diethyl phthalate); andPalatinol® K (Dibutylglycol phthalate). Further examples are thecommercially available adipates such as: Plastomoll® DOA(Di-(2-ethylhexyl)adipate) and Plastomoll® DNA (Diisononyl adipate).Further examples of suitable commercially available materials areVestinol® C (DBP), Vestinol® IB (DIBP), Vestinol® AH (DEHP), Witamol®110 (610P) and Witamol® 118 (810P).

For the purposes of the present invention, the terms “macropores” and“mesopores” are used as they are defined in Pure Appl. Chem., 45 (1976),79, namely as pores whose diameter is above 50 nm (macropores) or whosediameter is from 2 nm and 50 nm (mesopores). In the process of thepresent invention the one or more catalytically active metals aredeposited on a specific catalyst support. This catalyst support isprepared from one or more ordered mesoporous materials.

Preferred ordered mesoporous materials that may be used in the presentinvention, are those ordered mesoporous materials that may besynthesized using amphiphilic compounds as directing agents. Examples ofsuch materials are described in U.S. Pat. No. 5,250,282, the wholecontents of which are hereby incorporated by reference. Examples ofamphiphilic compounds are also provided in Winsor, Chemical Reviews,68(1), 1968. Other suitable ordered mesoporous materials of this typeare also described in “Review of Ordered Mesoporous Materials”, U.Ciesla and F. Schuth, Microporous and Mesoporous Materials, 27, (1999),131-49. Such materials include but are not limited to materialsdesignated as SBA (Santa Barbara) such as SBA-2, SBA-15 and SBA-16,materials designated as FSM (Folding Sheet Mechanism) such as FSM-16 andKSW-2, materials designated as MSU (Michigan State) such as MSU-S andMSU-X, materials designated as TMS or Transition Metal Sieves, materialsdesignated as FMMS or functionalized monolayers on mesoporous supportsand materials designated as APM or Acid Prepared Mesostructure.Particularly preferred ordered mesoporous materials are the silicate oraluminosilicate ordered mesoporous materials designated as M41S such asMCM-41, MCM-48 and MCM-50. These ordered mesoporous materials aredescribed in detail in U.S. Pat. No. 5,102,643, the whole contents ofwhich are hereby incorporated by reference. A particularly suitablesub-class of this family of materials for use in the present inventionare the mesoporous silicas designated as MCM-41 and MCM-48. MCM-41 isparticularly preferred and has a hexagonal arrangement of uniformlysized mesopores. MCM-41 molecular sieve materials are described indetail in U.S. Pat. No. 5,098,684, the whole contents of which arehereby incorporated by reference. The MCM-41 molecular sieves generallyhave a SiO₂/Al₂O₃ molar ratio when alumina is present that is greaterthan 100, preferably greater than 200, and most preferably greater than300.

In the present invention, the hydrogenation process utilizes a catalyst,which comprises a hydrogenation function in the form of a metal on asupport material comprising one or more ordered mesoporous materialswith a unique structure and pore geometry as described below. Preferredordered mesoporous materials are inorganic, porous, non-layeredmaterials which, in their calcined forms exhibit an X-ray diffractionpattern with at least one peak at a d-spacing greater than about 18Angstrom Units (Å). They also have a benzene adsorption capacity ofgreater than 15 grams of benzene per 100 grams of the material at 50torr and 25° C. In a preferred form, the support material ischaracterized by a substantially uniform hexagonal honeycombmicrostructure with uniform pores having a cell diameter greater than 2nm and typically in the range of 2 to 50 nm, preferably 3 to 30 nm andmost preferably from 3 to 20 nm. Most prominent among these materials isan ordered mesoporous material identified as MCM-41, which is usuallysynthesized as a metallosilicate with Broensted acid sites byincorporating a tetrahedrally coordinated trivalent element such as Al,Ga, B, or Fe within the silicate framework. The preferred forms of thesematerials are the aluminosilicates although other metallosilicates mayalso be utilized. MCM-41 is characterized by a microstructure with auniform, hexagonal arrangement of pores with diameters of at least about2 nm: after calcination it exhibits an X-ray diffraction pattern with atleast one d-spacing greater than about 18 Å and a hexagonal electrondiffraction pattern that can be indexed with a d₁₀₀ value of greaterthan about 18 Å, which corresponds to the d-spacing of the peak in theX-ray diffraction pattern. This material is described below and indetail in Ser. No. 07/625,245, now U.S. Pat. No. 5,098,684 (Kresge etal) and U.S. Pat. No. 5,102,643 to Kresge et al., both of which areincorporated by reference herein in their entirety.

The ordered mesoporous materials may be crystalline, that is havingsufficient order to provide a diffraction pattern such as, for example,by X-ray, electron or neutron diffraction, following calcination, withat least one peak. These mesoporous materials may be characterized bytheir structure, which includes large pore windows as well as highsorption capacities.

Ordered mesoporous materials as used in the present invention can bedistinguished from other porous inorganic solids by the regularity oftheir large open pores, whose pore size more nearly resembles that ofamorphous or paracrystalline materials, but whose regular arrangementand uniformity of size (pore size distribution within a single phase of,for example, +/−25%, usually +/−15% or less of the average pore size ofthat phase) resemble more those of crystalline framework materials suchas zeolites. The term “hexagonal” is intended to encompass not onlymaterials that exhibit mathematically perfect hexagonal symmetry withinthe limits of experimental measurement, but also those with significantobservable deviations from that ideal state. A working definition asapplied to the microstructure of the present invention would be thatmost channels in the material would be surrounded by six nearestneighbor channels at roughly the same distance. Defects andimperfections will cause significant numbers of channels to violate thiscriterion to varying degrees, depending on the quality of the material'spreparation. Samples which exhibit as much as +/−25% random deviationfrom the average repeat distance between adjacent channels still clearlygive recognizable images of the present ordered mesoporous materials.

The ordered mesoporous materials as used for preparation of the catalystsupport preferably have the following composition:M_(n/q)(W_(a)X_(b)Y_(c)Z_(d)O_(h))

wherein W is a divalent element, such as a divalent first row transitionmetal, e.g. manganese, cobalt and iron, and/or magnesium, preferablycobalt; X is a trivalent element, such as aluminium, boron, iron and/orgallium, preferably aluminium; Y is a tetravalent element such assilicon and/or germanium, preferably silicon; Z is a pentavalentelement, such as phosphorus; M is one or more ions, such as, forexample, ammonium, Group IA, IIA and VIIB ions, usually hydrogen, sodiumand/or fluoride ions; n is the charge of the composition excluding Mexpressed as oxides; q is the weighted molar 1 average valence of M; n/qis the number of moles or mole fraction of M; a, b, c, and d are molefractions of W, X, Y and 1 Z, respectively; h is a number of from 1 to2.5; and (a+b+c+d)=1. A preferred embodiment of the above crystallinematerial is when (a+b+c) is greater than d, and h=2. A furtherembodiment is when a and d=0, and h=2. In the as-synthesised form, themesoporous material has a composition, on an anhydrous basis, expressedempirically as follows:rRM_(n/q)(W_(a)X_(b)Y_(c)Z_(d)O_(h))

wherein R is the total organic material not included in M as an ion, andr is the coefficient for R, i.e. the number of moles or mole fraction ofR. The M and R components are associated with the material as a resultof their presence during synthesis of the material and are easilyremoved or, in the case of M, replaced by post-synthesis methodshereinafter more particularly described.

To the extent desired, the original M, e.g. ammonium, sodium orchloride, ions of the as-synthesised material can be replaced inaccordance with techniques well known in the art, at least in part, byion exchange with other ions. Preferred replacing ions include metalions, hydrogen ions, hydrogen precursor, e.g. ammonium, ions andmixtures thereof. Other ions rare earth metals and metals of Groups IA(e.g. K), IIA (e.g. Ca), VIIA (e.g. Mn), VIIIA (e.g. Ni), IB (e.g. Cu),IIB (e.g. Zn), IIIB (e.g. In), IVB (e.g. Sn), and VIIB (e.g. F) of thePeriodic Table of the Elements (Sargent-Welch Co. Cat. No. S-18806,1979) and mixtures thereof.

The preferred ordered mesoporous materials for use in the process of thepresent invention are ordered mesoporous silicas. The most preferredordered mesoporous silicas are those designated as M41S, with the mostpreferred being MCM-41.

Further examples of ordered mesoporous materials that may be used in theprocess of the present invention are the mesoporous silicas as describedin and prepared according to U.S. Pat. No. 5,951,962, the disclosure ofwhich is incorporated herein in its entirety.

In one embodiment of the present invention the catalyst may consistsolely of one or more active hydrogenation metals deposited on thesurfaces of one or more ordered mesoporous materials. In this embodimentthe catalyst is free of added inorganic binder. The ordered mesoporousmaterial with or without active metal deposited thereon may be shapedinto a wide variety of particle sizes. Generally speaking, the particlescan be in the form of a powder, a granule, or a molded product, such asan extrudate having particle size sufficient to pass through a 2 mesh(Tyler) screen and be retained on a 400 mesh (Tyler) screen. In caseswhere the catalyst is molded, such as by extrusion, the crystals can beextruded before drying or partially dried and then extruded.

In a further embodiment the ordered mesoporous materials may be formedinto composites with matrix materials resistant to the temperatures andother conditions employed in the hydrogenation process. Such materialsinclude active and inactive materials and synthetic or naturallyoccurring zeolites as well as inorganic materials such as clays and/oroxides such as alumina, silica or silica-alumina. The latter may beeither naturally occurring or in the form of gelatinous precipitates orgels including mixtures of silica and metal oxides. Use of a material inconjunction with the zeolite, i.e., combined therewith or present duringits synthesis, which itself is catalytically active may change theconversion and/or selectivity of the catalyst. These materials may beincorporated into naturally occurring clays, e.g., bentonite and kaolin,to improve the crush strength of the catalyst under commercial operatingconditions and function as binders or matrices for the catalyst. Theordered mesoporous material may be composited with the matrix materialin amounts from 99:01 to 05:95 by weight, preferably from 99:01 to10:90, more preferably from 99:01 to 20:80, and most preferably from99:01 to 50:50 ordered mesoporous material:matrix material. Preferably,if used the additional matrix material is kept to a minimum typicallyless than 50 wt % of the combined weight of ordered mesoporous materialand matrix material, ideally less than 40 wt %, preferably less than 30wt %, more preferably less than 20 wt %, more preferably less than 15 wt%, most preferably less than 10 wt % and in a most preferred embodimentless than 5 wt %. Formation of the composition may be achieved byconventional means including mulling the materials together followed byextrusion of pelletizing into the desired finished catalyst particles.Ideally the additional matrix material is macroporous or is a materialof mixed porosity i.e. both macroporous and mesoporous. The materials ofmixed porosity may have a pore distribution in which from about 5 toabout 50%, preferably from about 10 to about 45%, more preferably fromabout 10 to about 30 and in particular from about 15 to about 25%, ofthe pore volume is formed by macropores having pore diameters in therange from about 50 nm to about 10,000 nm and from about 50 to about95%, preferably from about 55 to about 90%, more preferably from about70 to about 90% and in particular from about 75 to about 85%, of thepore volume is formed by mesopores having a pore diameter of from about2 to about 50 nm where in each case the sum of the pore volumes adds upto 100%.

When used, the total pore volume of the mixed porosity material is fromabout 0.05 to 1.5 cm³/g, preferably from 0.1 to 1.2 cm³/g and inparticular from about 0.3 to 1.0 cm³/g. The mean pore diameter of themixed porosity material is preferably from about 5 to 20 nm, preferablyfrom about 8 to about 15 nm and in particular from about 9 to about 12nm. The surface area of the mixed porosity material is preferably fromabout 50 to about 500 m²/g, more preferably from about 200 to about 350m²/g and in particular from about 250 to about 300 m²/g of the support.

The surface area of the macroporous materials and mixed porositymaterials may be determined by the BET method using N₂ adsorption, inparticular in accordance with DIN 66131. The mean pore diameter and thesize distribution may be determined by Hg porosimetry, in particular inaccordance with DIN 66133.

The macroporous materials and mixed porosity materials that may be usedare, for example, macropore containing activated carbon, siliconcarbide, aluminum oxide, silicon dioxide, titanium dioxide, zirconiumdioxide, magnesium oxide, zinc oxide or mixtures of two or more thereof,with preference being given to using macropore containing alumina.

When an ordered mesoporous material and/or mixed porosity matrixmaterial are used, the finished catalyst may be a composition comprisinga support matrix of from 90 to 10% by weight MCM-41 and 10 to 90% byweight alumina, preferably 80 to 20% by weight MCM-41 and 20 to 80% byweight alumina, more preferably 80 to 40% by weight MCM-41 and 20 to 60%by weight of alumina, and as active metal component from 0.01 to 5 wt %Pt, preferably from 0.05 to 1 wt % Pt, more preferably from 0.1 to 0.5wt % Pt and most preferably 0.15 to 0.4 wt % Pt either alone or incombination with 0.01 to 5 wt % Pd, preferably from 0.05 to 2 wt % Pd,more preferably from 0.1 to 1.5 wt % Pd and most preferably 0.15 to 1.0wt % Pd. A particularly preferred composition comprises a support matrixof 70 to 60%, ideally 65% by weight MCM-41 and 30 to 40%, ideally 35% byweight alumina, and as active metal component, 0.1 to 0.4, ideally 0.3wt % Pt alone or in combination with 0.4 to 1.5, ideally 0.9 wt % Pd.

It is preferred that the catalyst used in the present inventioncomprises one or more active hydrogenation metals deposited on one ormore ordered mesoporous support materials free of added inorganic bindermaterial.

The hydrogenation catalyst includes an active metal as thehydrogenation-dehydrogenation component. Thehydrogenation-dehydrogenation component is provided by a metal orcombination of metals. Active metals that may be used are preferably oneor more metals of transition group VIII of the Periodic Table.Preference is given to using platinum, rhodium, palladium, cobalt,nickel or ruthenium or a mixture of two or more thereof as active metal.A particular preference is given to using ruthenium, platinum, palladiumor mixtures of two or more thereof. A particularly preferred activemetal is ruthenium.

The content of the metal component will vary according to its catalyticactivity. Thus, the highly active noble metals may be used in smalleramounts than the less active base metals. For example, about 1 wt.percent or less palladium or platinum will be effective. The presentsupport materials are, however, notable in that they are capable ofincluding a greater proportion of metal than previous support materialsbecause of their extraordinarily large surface area. The metal componentmay exceed about 30 percent in a monolayer. The hydrogenation componentcan be exchanged onto the support material, impregnated into it orphysically admixed with it.

The active metal content is generally from about 0.01 to about 30% byweight, preferably from about 0.01 to about 5% by weight and inparticular from about 0.1 to about 5% by weight, in each case based onthe total weight of the catalyst used. A preferred catalyst is one thatcomprises ruthenium alone or in combination with one or more additionalactive metals at a total content of less than 5% by weight of activemetal and preferably at a total content of less than 2% by weight ofactive metal. Preferably the content of ruthenium is from about 0.01 to2%, more preferably 0.1 to 1% by weight of the total catalyst.

The catalysts according to the present invention may be producedindustrially by application of the one or more catalytically activemetals to the desired support. The application may be achieved bysteeping the support in aqueous metal salt solutions, for exampleruthenium or palladium or platinum salt solutions, by sprayingappropriate metal salt solutions onto the support or by other suitablemethods. Suitable metal salts for preparing the metal salt solutions arethe nitrates, nitrosyl nitrates, halides, carbonates, carboxylates,acetylacetonates, chloro complexes, nitrito complexes or amine complexesof the corresponding metals, with preference being given to the nitratesand nitrosyl nitrates and most preferably the nitrosyl nitrates.

In the case of catalysts, which have a plurality of active metalsapplied to the support, the metal salts or metal salt solutions can beapplied simultaneously or in succession.

When the ordered mesoporous material is used in combination with amatrix material it is preferred that the active hydrogenation metal isapplied to the ordered mesoporous material before it is combined withthe matrix material.

The ordered mesoporous materials either with or without matrix material,which have been coated or impregnated with the metal salt solution, maysubsequently be dried, preferably at from 100 to 150° C. If desired,these supports can be calcined at from 200 to 600° C., preferably from350 to 450° C.

The dried and/or calcined ordered mesoporous materials either with orwithout matrix material, are subsequently activated by treatment in agas stream comprising free hydrogen at from 30 to 600° C., preferablyfrom 100 to 450° C., and in particular from 100 to 300° C. The gasstream preferably consists of from 50 to 100% by volume of H₂ and from 0to 50% by volume of N₂.

If a plurality of active metals are applied to the support and theapplication is carried out in succession, the support can be dried atfrom 100 to 150° C. and, if desired, calcined at from 200 to 600° C.after each application or impregnation.

Chemisorption measurements are commonly used to estimate the size ofsupported metal catalysts and metal surface area. The general method formeasuring metal surface area by chemisorption is described in J.Lemaitre et al., “Characterization of Heterogenous Catalysts”, edited byFrancis Delanney, Marcel Dekker, New York (1984), pp. 310-324. The totalmetal surface area on the catalyst is preferably from 0.01 to 10 m²/g,particularly preferably from 0.05 to 5 m²/g and more preferably from0.05 to 3 m²/g of the catalyst. From chemisorption measurements, the %dispersion (% of metal atoms that populate the surface of the metalparticles) can be estimated since a properly chosen titrant used in thechemisorption measurements adsorbs only on metal atoms populating thesurface. Consequently higher dispersion values indicate smallerparticles with more of the metal atoms populating the surface. For manyhydrogenation reactions, activity correlates with dispersion. Thepreferred method for determining metal dispersion is by using hydrogenas the chemisorption probe molecule under high vacuum static conditionsas follows. The sample is held at a temperature of 40° C. and an 8-pointisotherm (with pressures between 80 and 400 torr) is obtained using H₂as the chemisorption probe molecule. The linear portion of this isothermis extrapolated to zero pressure to obtain the total quantity ofhydrogen chemisorbed; this is the combined dispersion. The sample isthen evacuated at 40° C. to remove any weakly adsorbed hydrogen and thetitration repeated to determine what is referred to as weak adsorptionisotherm. The linear portion of this weak adsorption isotherm isextrapolated to zero pressure to obtain the quantity of weaklychemisorbed hydrogen. Subtraction of these two values for combineddispersion and weak dispersion yields the strongly held chemisorbedquantity. Thus this method provides values for the total metaldispersion, the dispersion due to weakly chemisorbed hydrogen anddispersion due to strongly chemisorbed hydrogen. The value for thestrongly chemisorbed hydrogen is an accurate indication of metaldispersion. In many prior art references the metal dispersion figuresprovided are based on the total chemisorbed probe and are not split intostrong and weak components. In the present invention it is preferredthat the hydrogenation catalyst used have dispersion values relating tothe strongly chemisorbed component in excess of 20% more preferably inexcess of 25% and most preferably in excess of 30%. In addition totaldispersion values in excess of 45% preferably in excess of 50%, morepreferably in excess of 55%, and most preferably in excess of 60% areachieved. Preferably 40% or more of the total metal dispersion relatesto the strongly chemisorbed component, more preferably 45% or more andmost preferably 50% or more.

In a further aspect of the present invention prior to deposition ofhydrogenation metal on the desired ordered mesoporous support thehydrogenation metal salt solutions used may be combined with one or moreamines to form a mixture with the solution and this mixture is appliedto the ordered mesoporous support. Preferred amines includealkanolamines such as triethanolamine or amino acids such as L-arginine.

In the process of the present invention, the hydrogenation is generallycarried out at from about 50 to 250° C., preferably from about 70 to220° C., most preferably 75 to 160° C. The pressures used here aregenerally above 10 bar, more preferably from about 20 to about 300 bar,and most preferably 50 to 300 bar, especially 80 to 300 bar. Preferablythe pressure is greater than 100 bar and more preferably greater than130 bar.

The process of the present invention may be carried out eithercontinuously or batchwise, with preference being given to carrying outthe process continuously.

When the process is carried out continuously, the amount of thebenzenepolycarboxylic acid or ester to be hydrogenated or of the mixtureof two or more thereof is from about 0.05 to about 3 kg per liter ofcatalyst per hour, preferably from about 0.1 to about 2 kg per liter ofcatalyst per hour, more preferably from 0.2 to 1.5 kg per liter ofcatalyst per hour and most preferably from 0.2 to about 1 kg per literof catalyst per hour.

As hydrogenation gases, it is possible to use any gases which comprisefree hydrogen and do not contain harmful amounts of catalyst poisonssuch as CO, CO₂, COS, H₂S and amines. For example, waste gases from areformer can be used. Preference is given to using pure hydrogen as thehydrogenation gas.

The hydrogenation of the present invention can be carried out in thepresence or absence of a solvent or diluent, i.e. it is not necessary tocarry out the hydrogenation in solution.

However, preference is given to using a solvent or diluent. Any suitablesolvent or diluent may be used. The choice is not critical as long asthe solvent or diluent used is able to form a homogeneous solution withthe benzenepolycarboxylic acid or ester to be hydrogenated. For example,the solvents or diluents may also comprise water although it ispreferred that they are free of water. Examples of suitable solvents ordiluents include the following: straight-chain or cyclic ethers such astetrahydrofuran or dioxane, and also aliphatic alcohols in which thealkyl radical preferably has from 1 to 10 carbon atoms, in particularfrom 3 to 6 carbon atoms. Examples of alcohols, which are preferablyused, are i-propanol, n-butanol, i-butanol and n-hexanol. Mixtures ofthese or other solvents or diluents can likewise be used.

The amount of solvent or diluent used is not restricted in anyparticular way and can be selected freely depending on requirements.However, preference is given to amounts which lead to a 10-70% strengthby weight solution of the benzenepolycarboxylic acid or ester to behydrogenated.

In the process of the present invention it is also possible to use oneor more derivates of benzenepolycarboxylic acids in the unpurified statethat is in the presence of one or more starting materials for theirmanufacture such as for example alcohol in the case of esterderivatives. Also present may be traces of monoester derivatives,tin-reacted acid such as phthalic acid, sodium monoester derivatives andsodium salts of the acids. In this aspect the benzenecarboxylic acidderivative is hydrogenated prior to purification and after hydrogenationis then sent to process finishing for stripping, drying and polishingfiltration. In this aspect the benzenecarboxylic acid derivative may bean intermediate feed containing high levels of alcohol in the case ofester derivatives. There may be present 5 to 30% excess alcohol thanthat required to achieve complete esterification of the acid. In oneembodiment there may be an intermediate feed containing 8 to 10 wt %isononyl alcohol in di-isononyl phthalate.

In the process of the present invention the desired products are one ormore cyclohexyl materials derived from the hydrogenation of thecorresponding benzenepolycarboxylic acid or derivatives thereof. Ideallythe benzenepolycarboxylic acid or derivatives thereof are converted tothe desired product with a high degree of selectivity and with themaximum conversion possible of the benzenepolycarboxylic acid orderivatives thereof. Hydrogenations of this type often result inundesirable by-products of relatively low molecular weight and lowboiling point; these by-products are referred to as “lights”. In thecontext of the present invention “lights” are defined as materials inthe as hydrogenated reaction product that are eluted before the objectcyclohexyl materials when the as hydrogenated reaction product isanalyzed by Gas Liquid Chromatography. Details for one suitable methodfor determining the “lights” content of a product obtained by theprocess of the present invention is provided in the specific examples.When using the process of the present invention it is possible to obtaingreater than 95% conversion of the starting material (one or morebenzenepolycarboxylic acid or derivatives thereof), whilst at the sametime producing less than 1.5% by weight based on the total weight ofreaction product of “lights”. In the process of the present inventionthe product obtained directly from the hydrogenation reaction ideallycontains the object cyclohexyl derivative(s) in an amount that equatesto 97 or greater mole % conversion of the starting material, preferably98.5 or greater mole % conversion, more preferably 99 or greater mole %conversion, and most preferably 99.9 or greater mole % conversion. Inthe process of the present invention the product obtained directly fromthe hydrogenation reaction ideally contains 1.3% or less, preferably1.0% or less, more preferably 0.75% or less, even more preferably 0.5%or less, and in the most preferable embodiment less than 0.3% by weightbased on the total weight of the reaction product of “lights”. When ashydrogenated products of this level of purity are obtained it may bepossible to use these materials directly in certain applications withoutthe need for further purification of the as hydrogenated product such asplasticisers for plastics products.

The process of the present invention is further illustrated by means ofthe following non-limiting examples.

EXAMPLES Example 1 Preparation of MCM-41

A sample of MCM-41 (40 Å) was prepared in accordance with the methoddescribed below, which corresponds to Example 21 of U.S. Pat. No.5,837,639. The following mixture (parts by weight—pbw) was charged to anautoclave:

83.7 pbw Cetyltrimethylammonium (CTMA) hydroxide prepared by contactinga 29 wt. % N,N,N-trimethyl-1-hexadecylammonium chloride solution with ahydroxide-for halide exchange resin, 1.7 pbw sodium aluminate, 41.1 pbwtetramethylammonium silicate (10% aqueous solution), and 10.5 pbwprecipitated hydrated silica (HiSil)

The mixture was crystallized at 100° C. for 20 hours with stirring underautogeneous pressure. The resulting product was recovered by filtrationand dried in air at ambient temperature. The product was then calcinedat 540° C. for one hour in nitrogen, followed by six hours in air. Thecalcined product had a surface area of 1120 m²/g and the followingequilibrium adsorption capacities in gram/100 grams:

H₂O 10.8 Cyclohexane >50 n-Hexane >50 Benzene 67

The product was identified as MCM-41 with an X-ray diffraction patternthat included a very strong relative intensity line at 38.4+/−2.0 Å, andweak lines at 22.6+/−1.0, 20.0+/−1.0, and 15.2+/−Å.

Example 2 Preparation of MCM-41

A sample of MCM-41 (40 Å) was prepared in accordance with the followingmethod:

The following mixture (parts by weight—pbw) was charged to an autoclave:

26.8 pbw distilled water, 3.5 pbw Cetyltrimethylammonium (CTMA) chloride(29 wt. % aqueous solution), 4.55 pbw precipitated hydrated silica(Ultrasil PM), 1 pbw Tetramethylammonium hydroxide (25 wt. % aqueous)

The mixture was crystallized at 150° C. for 20 hours with stirring underautogeneous pressure. The resulting product was recovered by filtrationand dried in air at ambient temperature. The product was then calcinedat 540° C. for one hour in nitrogen, followed by six hours in air. Theproduct was identified as MCM-41. The calcined product has a surfacearea of 903 m²/g and a pore size (determined by nitrogen adsorption) of3.8 nm. The analyses are as follows:

Silica 96.8 wt. % Alumina 0.1018 wt. % Sodium 0.0300 wt. % Carbon 0.11wt. %Sorption capacities were as follows:

H₂O 5.9 wt. % Cyclohexane 53.9 wt. % n-Hexane 44.1 wt. %

Example 3 Preparation of Hydrogenation Catalyst—Ruthenium on MCM-41

A solution was prepared by combining with stirring 16.6 grams ofruthenium (III) nitrosyl nitrate aqueous solution with 25.7 grams oftriethanolamine and 25.7 grams of distilled water. This solution wasadded slowly to 25 grams of MCM-41 of Example 2 and dried overnight at100° C. The catalyst was then calcined to 400° C. for three hours inflowing air. The ruthenium content was a nominal 0.5%.

Example 4 Preparation of Hydrogenation Catalyst—Ruthenium onMCM-41+γ-Alumina

A solution was prepared by combining with stirring 16.6 grams ofruthenium (III) nitrosyl nitrate aqueous solution with 10.7 grams of DIwater and 10.7 grams of triethanolamine. This solution was added slowlyto 25 grams of 1/16-inch MCM-41 (Example 2) bound with gamma aluminaextrudates (65/35 weight % MCM-41/gamma alumina) and dried overnight at100° C. The catalyst was then calcined to 400° C. for three hours inflowing air. The ruthenium content was a nominal 0.5%.

Example 5 Preparation of Hydrogenation Catalyst—Ruthenium on γ-Alumina

A solution was prepared by combining with stirring 16.6 grams ofruthenium (III) nitrosyl nitrate aqueous solution with 9.0 grams of DIwater. This solution was added slowly to 25 grams of 1/16-inch gammaalumina extrudates and dried overnight at 100° C. The catalyst was thencalcined to 400° C. for three hours in flowing air. The rutheniumcontent was a nominal 0.5%.

Example 6 Preparation of Hydrogenation Catalyst—Ruthenium on γ-alumina

A solution was prepared by combining with stirring 16.6 grams ofruthenium (III) nitrosyl nitrate aqueous solution with 4.2 grams of DIwater and 4.2 grams of triethanolamine. This solution was added slowlyto 25 grams of 1/16-inch gamma alumina extrudates and dried overnight at100° C. The catalyst was then calcined to 400° C. for three hours inflowing air. The ruthenium content was a nominal 0.5%.

Example 7 Reduction of Metal Component of Hydrogenation Catalysts

The catalysts used in the hydrogenation of Example 8 were activatedunder two sets of conditions a) and b) as follows:

a) Catalyst particles (10/20 mesh) were loaded into a stainless-steelcatalyst basket then installed in a 300 cm³ autoclave. Metal reductionwas conducted under a continuous atmospheric hydrogen flow of ˜100 cm³min⁻¹ at 200° C. for 18 hours.

b) Catalyst particles (10/20 mesh) were loaded into a stainless-steelcatalyst basket then installed in a 300 cm³ autoclave. Metal reductionwas conducted under a static hydrogen pressure of 1250 psig (approx 86bar) at 200° C. for 14 hours.

Example 8 Hydrogenation of Di-isononyl phthalate (DINP)

After activation according to Example 7 the autoclave was cooled. To thecooled autoclave was added 137.4-194.5 g (0.28-0.46 mol) of liquid DINP((Jayflex DINP (CAS No. 68515-48-0). The autoclave was sealed, heated tothe hydrogenation temperature of 80 or 120° C., and pressurized withhydrogen to either a pressure of 840 psig (approx 58 bar) or 3000 psig(approx 207 bar). Hydrogenation was continued for between 3 to 7.5 hrs.At the end of the hydrogenation period the product was analyzed todetermine the conversion of DINP and assess the level of lightsformation. Conversion of DINP was calculated directly based on the peakareas of residual aromatic proton resonance in 1H NMR spectra. Thelights content of the sample was determined by Gas Liquid Chromatographyusing a DB-1 column (60 m×0.25 mm×0.25 μm), operated at 40-275° C. at aramp rate of 10° C./min and holding at 275° C. for 35 minutes. Thelights were determined as being all product peaks, which eluted inwithin the first 24.5 minutes. Components eluted thereafter wereconsidered as the desired cyclohexyl products.

The conversions and selectivities for the various hydrogenations areprovided in Table 1. This data shows that when MCM-41 is used as thesole catalyst support (Examples 8c and 8e) levels of conversion inexcess of 99% may be achieved whilst at the same time resulting inrelatively low levels of lights formation. There is also a clear benefitof using a catalyst comprising a mixed support of MCM-41 and aluminawhen compared to the use of alumina alone as catalyst support. Thebenefits of using MCM-41 as the sole support are most marked at higherhydrogenation pressures where there is approximately a 50% reduction inlights formation compared to the conventional amorphous aluminasupported ruthenium catalysts.

TABLE 1 Weight Weight Temp Pressure Time Conversion Lights HydrogenationExample Catalyst DINP (g) Catalyst (g) (° C.) (psig) (h) mole % (wt %)Method 8a 1 Run Ru on Al₂O₃ (Ex 6) 193.6 10.0 120° 840 7.5 97.1 0.90Example 7b 8b 3 Runs Ru on MCM-41/Al₂O₃ (Ex 4) 192.1 10.01 120° C. 8407.5 97 0.74 Example 7b 8c 2 Runs Ru on MCM-41 crystal (Ex 3) 194.5 10.0120° C. 840 7.5 99+ 0.44 Example 7b 8d 2 Runs Ru on Al₂O₃ (Ex 5) 154.88.1 120° C. 3000 3 96.0 0.64 Example 7a 8e 1 Run Ru on MCM-41 Crystal(Ex 3) 137.4 6.07 120° C. 3000 3 99.9+ 0.35 Example 7a

1. A process for hydrogenating one or more benzenepolycarboxylic acidsor one or more derivatives thereof, or a mixture of one or morebenzenepolycarboxylic acids or one or more derivatives thereof, thederivative being an ester produced by the esterification of the acidwith an alcohol, comprising contacting benzenepolycarboxylic acid or thederivative thereof or the mixture with a hydrogen-containing gas in thepresence of a catalyst in the presence of 5 to 30% excess alcohol thanthat required to achieve complete esterification of the acid, saidcatalyst comprising one or more catalytically active Group VIII metalsapplied to one or more mesoporous support materials; wherein the processhydrogenates at 97% or greater mole % conversion and wherein the productproduced by the process comprises less than 1.5% of lights materials, byweight based on the total weight of the product.
 2. The process of claim1, wherein said excess alcohol is from 8 to 10 wt %.
 3. The process ofclaim 1, wherein said catalyst support comprises one or more mesoporousmaterials.
 4. The process of claim 1, wherein said support comprisesordered mesoporous silica.
 5. The process of claim 1, furthercomprising, after hydrogenation, the steps of stripping and filtration.6. The process of claim 1, wherein one or more derivatives is selectedfrom esters.
 7. The process of claim 6, wherein the esters are alkylesters.
 8. The process of claim 6, wherein the esters are selected fromthe group consisting of monoesters, diesters, triesters, tetraesters,and mixtures thereof.
 9. The process of claim 6, wherein the esters areselected from the group consisting of phthalates, terephthalates,trimellitates, trimesates, hemimellitates, pyromellitates, and mixturesthereof.
 10. The process of claim 6, wherein the esters are selectedfrom the group consisting of alkyl phthalates, alkyl terephthalates,alkyl trimellitates, alkyl trimesates, alkyl hemimellitates, alkylpyromellitates, and mixtures thereof.
 11. The process of claim 1,wherein the derivative is di-isononyl phthalate.
 12. The process ofclaim 1, wherein the alcohol is isononyl alcohol.
 13. The process ofclaim 1, wherein the process hydrogenates at 98.5% or greater mole %conversion.
 14. The process of claim 1, wherein the process hydrogenatesat 99% or greater mole % conversion.
 15. The process of claim 1, whereinthe process further comprises an intermediate feed containing from 8 to10 wt % isononyl alcohol in di-isononyl phthalate.
 16. The process ofclaim 1, wherein the product produced by the process comprises 1.0% orless of lights materials, by weight based on the total weight of theproduct.
 17. The process of claim 1, wherein the product produced by theprocess comprises 0.75% or less of lights materials, by weight based onthe total weight of the product.
 18. The process of claim 1, wherein theproduct produced by the process comprises 0.5% or less of lightsmaterials, by weight based on the total weight of the product.